Generally, a lamp device is a light source for brightening a dark place or at night by means of light emitted from a lamp mounted in a lamp case. Most glow lamps, or a part of fluorescent lamps, among the lamp devices are configured to make a connection by fitting each of them into a screwed socket in order to receive power, which ensures their ordinary usage, regardless of their installing type such as an exposed type or a buried type on the wall.
The socket-type lamp device is mainly used in places such as street, apartment or house passage, stairway, the porch, or bathroom where management for lighting time is required due to frequent passage of persons in order to prevent an unnecessary waste of power.
In order to solve this problem, a conventional automatic control lamp device includes, together with a lamp as a light source, an illumination sensor (e.g., a CdS sensor) for sensing brightness of a surrounding place where recognition of illumination at day and night and constant turning on/off are required, and an infrared sensor (e.g., a Passive Infra-Red (PIR) sensor) for controlling the lamp to be automatically turned on or off according to the presence of the subject at a place where the lamp should be turned on/off according to entrance and exit of a person, selectively or in combination as necessary. The sensor(s) is generally provided in one lamp case having a body and a cover with each sensor being separated from the lamp.
That is to say, the conventional automatic control lamp device automatically turns on when the illumination sensor or the human-responsive sensor (or, the infrared sensor) installed in one lamp case together with the lamp senses the set brightness or the passage of a person and then allows supply of power to the lamp, and then automatically turns off a certain time after, for example, the passage of the human, thereby ensuring automatic control of the lamp.
Thus, the automatically controlled lamp device as mentioned above does not emit light if the surrounding illumination is lower than a predetermined level or the presence or movement of a human is not detected, thereby preventing an unnecessary waste of energy.
However, the conventional automatic control lamp device may sense surrounding illumination regardless of the presence of a human, so it turns on at a certain condition for a set time and then turns off. In addition, a conventional lamp device with the infrared sensor for sensing a human may turn on regardless of the brightness of the surroundings. In addition, another lamp device in which at least one improved sensor is covered by a cover separately from a lamp may be used for a dedicated installation, so its usage is impossible if the dedicated installation is not equipped. Thus, such a lamp device is very inconvenient to use and cumbersome to change or repair. In addition, since a lamp should be separately provided in the lamp case together with many sensors having different functions as necessary, the lamp device has a complicated configuration and a large size and suffers from deficient productivity due to the increased number of processes.